1. Field of the Invention
This invention relates to an improved catalytic process for producing hydrogen peroxide from hydrogen and oxygen.
2. Background of the Invention
The following references disclose catalytic processes for producing hydrogen peroxide from hydrogen and oxygen. One problem associated with known direct combination processes is that product yields are too low for large scale commercial applications. Improved processes for producing hydrogen peroxide in high concentrations are of significant interest to the chemical industry.
U.S. Pat. No. 3,336,112, issued to Hooper, discloses a process for producing hydrogen peroxide which comprises contacting hydrogen and oxygen with a solid catalyst in the liquid phase in the presence of water and a hydrogen peroxide stabilizer, for example, a sequestrative hydrogen peroxide stabilizer.
U.S. Pat. No. 3,361,533, also issued to Hooper, discloses a process for the production of hydrogen peroxide which comprises contacting hydrogen and oxygen with a solid catalyst in the liquid phase in the presence of water, an acid and a non-acidic oxygen-containing organic compound.
U.S. Pat. No. 3,433,582, issued to Campbell, discloses a process for producing hydrogen peroxide which comprises contacting hydrogen and oxygen with a solid catalyst in a liquid medium containing water and dissolved boric acid. The patent discloses that there may also be present a second radical, especially a halogen or pseudo-halogen.
U.S. Pat. No. 4,007,256, issued to Kim et al., discloses a process for the production of hydrogen peroxide by contacting hydrogen and oxygen with a supported palladium catalyst in the presence of water, an organic nitrogen-containing compound and a strong acid.
Posplova et al., Russian Journal of Physical Chemistry, 35(2):143-148 (1961) disclose a palladium-catalyzed synthesis of hydrogen peroxide from hydrogen and oxygen. Palladium black and palladium deposited on alumina gel, tungstic anhydide, silica gel, and bone charcoal were used as catalysts.
U.S. Pat. No. 4,009,252, issued to Izumi et al., discloses a process for preparing hydrogen peroxide by a catalytic reaction of hydrogen and oxygen in an aqueous medium containing a platinum-group catalyst. The process is characterized in that the partial pressure of hydrogen and the partial pressure of oxygen in the gaseous phase of the reaction system are maintained at at least 0.5 atmosphere and at least 1.0 atmosphere, respectively. The platinum group catalyst is caused to be present in an amount, calculated as metal, of at least a minimum effective catalytic amount up to 30 mg per 100 mL of the aqueous medium.
U.S. Pat. No. 4,279,883, issued to Izumi et al., discloses an improved process for preparing hydrogen peroxide by reacting hydrogen with oxygen in the presence of a catalyst in an aqueous medium containing hydrogen peroxide; the improvement comprises using an aqueous medium which contains dissolved hydrogen and a platinum-group catalyst having hydrogen adsorbed thereto. Materials such as carbon, silica, and a number of other materials are described as being suitable for supporting the platinum group metal.
U.S. Pat. No. 4,335,092, issued to Dalton, Jr. et al., discloses a process for preparing hydrogen peroxide in which hydrogen and oxygen are contacted with a supported palladium catalyst in the presence of a methanol solution. Preferably, the solution contains up to 1.0% by weight of formaldehyde and is at least 0.001 N in hydrochloric acid.
U.S. Pat. No. 4,336,238, issued to Dalton, Jr. et al., discloses an improvement in a process for producing hydrogen peroxide by contacting a mixture of hydrogen and oxygen with a palladium on carbon catalyst in the presence of an acidic aqueous liquid capable of inhibiting decomposition of hydrogen peroxide. The improvement comprises prolonging the useful life of the catalyst by continuous removal of palladium salts produced by solubilization of the catalyst from the acidic aqueous liquid. The medium employed comprises up to 95% by volume of an organic solvent.
U.S. Pat. No. 4,336,239, issued to Dalton, Jr. et al., discloses an improvement in hydrogen peroxide synthesis from hydrogen and oxygen in an acidic medium containing an oxygenated or nitrogenous organic compound using a supported Group VIII noble metal catalyst. The improvement comprises using an oxygen/hydrogen ratio higher than about 3.4 and a catalyst level above 30 mg per 100 mL of medium.
U.S. Pat. No. 4,379,778, issued to Dalton, Jr. et al., discloses improvements in palladium-carbon atalysts for the production of hydrogen peroxide from a mixture of hydrogen and oxygen in the presence of an aqueous liquid capable of inhibiting the decomposition of hydrogen peroxide. The improvement comprises pretreating the catalyst with an aldehyde or ketone, and, preferebly, also pretreating the catalyst with a dilute solution of hydrochloric acid. Improved catalysts are obtained by reducing a soluble palladium compound deposited on a high surface area non-graphitic carbon base, in the form of a dried powder, with hydrogen at 27.degree.-200.degree. C.
U.S. Pat. No. 4,389,390, issued to Dalton, Jr., et al., discloses an improvement in a process for producing hydrogen peroxide by contacting a mixture of hydrogen and oxygen with a palladium on carbon catalyst in the presence of an acidic liquid capable of inhibiting decomposition of hydrogen peroxide. The improvement comprises prolonging the useful life of the catalyst by continuous removal of palladium salts produced by solubilization of the catalyst from the acidic liquid, preferably by employing high surface area activated carbon as the catalyst support and adsorbent for palladium salts.
The following four publications disclose the danger inherent in producing hydrogen peroxide in the presence of an organic component. Swern, Organic Peroxides, Wiley-Interscience, New York, page 26, (1970) discloses the preparation of peroxy compounds from aldehydes and hydrogen peroxide. The reference discloses that extreme caution should be taken when handling and preparing ketone peroxides, since some are very sensitive and explode with violence. Schumb et al., Hydrogen Peroxide, Reinhold Publishing Corporation, page 179 (1955) describes explosive characteristics of solutions of methyl alcohol, ethyl alcohol, or glycerine in concentrated hydrogen peroxide. Halle, Chemical and Engineering News, 62(27):4 (1984) describes potential hazards associated with organic peroxides. Schwoegler, Chemical and Engineering News, 63(1):6 (1985) describes the shock sensitivity Of acetone peroxides.
U.S. Pat. No. 4,681,751, issued to Gosser, discloses a method for making hydrogen peroxide from hydrogen and oxygen employing a catalytically effective amount of Pd on adsorbent carbon, an aqeuous reaction medium and superatmospheric pressure.
Allowed (commonly assigned) U.S. application Ser. No. 932,360, filed Nov. 19, 1986 in the names of Gosser and Schwartz, discloses an improved method for making hydrogen peroxide in which the reaction is carried out in the presence of hydrogen ions and bromide ions in a molar ratio of at least about 2:1.